home *** CD-ROM | disk | FTP | other *** search
/ Graphics Plus / Graphics Plus.iso / general / modelers / geomview / source.lha / Geomview / src / bin / geomutil / ucd / vec4.h < prev   
Text File  |  1992-10-22  |  412b  |  14 lines
  1. #define VSUB3(p0, p1, p2)        \
  2.     { (p2)->x  = (p1)->x - (p0)->x;        \
  3.     (p2)->y  = (p1)->y - (p0)->y;        \
  4.     (p2)->z  = (p1)->z - (p0)->z;  }
  5.  
  6. #define VDOT3(p0, p1)        \
  7.     ((p0)->x*(p1)->x + (p0)->y*(p1)->y + (p0)->z*(p1)->z)
  8.  
  9. #define NORMALIZE3(xx)    \
  10.     {float x = sqrt((xx)->x*(xx)->x + (xx)->y*(xx)->y +(xx)->z*(xx)->z); \
  11.     if (x == 0) x = 1.0;    \
  12.     x = 1.0/x;        \
  13.     (xx)->x    *= x;   (xx)->y *= x;   (xx)->z *= x;}    
  14.